From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Sender: Tejun Heo Date: Wed, 11 Apr 2018 07:51:23 -0700 From: Tejun Heo To: Alexandru Moise <00moses.alexander00@gmail.com>, Joseph Qi , Bart Van Assche Cc: axboe@kernel.dk, shli@fb.com, nborisov@suse.com, arnd@arndb.de, gregkh@linuxfoundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] blk-cgroup: remove entries in blkg_tree before queue release Message-ID: <20180411145123.GJ793541@devbig577.frc2.facebook.com> References: <20180407102148.GA9729@gmail.com> <20180409220938.GI3126663@devbig577.frc2.facebook.com> <20180411101242.GA2322@gmail.com> <20180411142019.GG793541@devbig577.frc2.facebook.com> <20180411142859.GB2322@gmail.com> <20180411144616.GI793541@devbig577.frc2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180411144616.GI793541@devbig577.frc2.facebook.com> List-ID: Hello, (cc'ing Bart) On Wed, Apr 11, 2018 at 07:46:16AM -0700, Tejun Heo wrote: > Hello, > > On Wed, Apr 11, 2018 at 04:28:59PM +0200, Alexandru Moise wrote: > > > Ah, that changed recently. Can you please check out the current > > > upstream git master? > > > > > Just did, without my patch I see this crash: > > lol I was looking at the old tree, so this is the fix for the new > breakage introduced by the recent change. Sorry about the confusion. > Joseph, can you please take a look? Oh, it wasn't Joseph's change. It was Bart's fix for a problem reported by Joseph. Bart, a063057d7c73 ("block: Fix a race between request queue removal and the block cgroup controller") created a regression where a request_queue can be destroyed with blkgs still attached. The original report is.. http://lkml.kernel.org/r/20180407102148.GA9729@gmail.com Thanks. -- tejun